On top quark mass effects to $gg\to ZH$ at NLO

We compute next-to-leading order QCD corrections to the process $gg\to ZH$. In the effective-theory approach we confirm the results in the literature. We consider top quark mass corrections via an asymptotic expansion and show that there is a good convergence below the top quark threshold which describes approximately {\num a quarter} of the total cross section. Our corrections are implemented in the publicly available {\tt C++} program {\tt ggzh}.